Scientists using neuroimaging tools, such as MRI, NIRS, EEG, and MEG, use average MRI templates for locating brain structures (stereotaxic atlases), combining brains across different participants, segmenting priors for identification of cortical tissues (gray matter, white matter, CSF), and determining the relation between scalp locations and the brain (e.g., EEG, NIRS, MEG). Average MRI templates that are usually used have been based on single adult MRIs or average templates from young adults. Use of these templates with pediatric (newborns, infants, children), adolescent, and elderly populations results in irregular registrations, misspecification of segmented data, and poor fits for stereotaxic atlases. The ?Neurodevelopmental MRI Database? was created to address this issue. It provides MRI templates form 2 weeks through 89 years of age, as well as supporting materials (segmenting priors, atlases, EEG and NIRS placements). The data are presented in fine-grained ages (e.g., 1.5 month intervals through 1 year; 6 month intervals through 19.5 years; 5 year intervals from 20 through 89 years). The current project will add new participants to the average MRI templates, refine the MRIs for wider use with MRI processing programs, and plan a transition from distribution through the PI's online storage site to an open-access distribution site. This project will enhance the current data and facilitate the sharing of this important resource.